EP0351609A2 - Transducteur de position - Google Patents

Transducteur de position Download PDF

Info

Publication number: EP0351609A2
Authority: EP; European Patent Office
Prior art keywords: coil; position transducer; slider; along; turns
Prior art date: 1988-07-22
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.): Granted

Application number

EP89111971A

Other languages

German (de)

English (en)

Other versions

EP0351609A3 (fr

EP0351609B1 (fr

Inventor

Antonio Boscolo

Silvana Medeot

Giancarlo Arrigoni

Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Zeltron Istituto Zanussi per la Ricerca SpA

Original Assignee

Zeltron Istituto Zanussi per la Ricerca SpA

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)

1988-07-22

Filing date

1989-06-30

Publication date

1990-01-24

1989-06-30 Application filed by Zeltron Istituto Zanussi per la Ricerca SpA filed Critical Zeltron Istituto Zanussi per la Ricerca SpA

1989-06-30 Priority to AT89111971T priority Critical patent/ATE93960T1/de

1990-01-24 Publication of EP0351609A2 publication Critical patent/EP0351609A2/fr

1991-03-06 Publication of EP0351609A3 publication Critical patent/EP0351609A3/fr

1993-09-01 Application granted granted Critical

1993-09-01 Publication of EP0351609B1 publication Critical patent/EP0351609B1/fr

2009-06-30 Anticipated expiration legal-status Critical

Status Expired - Lifetime legal-status Critical Current

Images

Classifications

- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
- G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
- G01D5/2006—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils
- G01D5/202—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils by movable a non-ferromagnetic conductive element

Definitions

the present invention relates to an improved position transducer, i.e. a means adapted to transform the position of a control element along a direction, within a predetermined field, into a corresponding different physical quantity, such as an electrical signal, for example.
a conventional position transducer of this type comprising, for example, a potentiometer equipped with a slider sliding along a resistor, in contact therewith, and having a predetermined configuration and length. If the potentiometer is connected in a suitable electric circuit, it is readily possible to transform the position of the slider relative to the resistor into a corresponding value of electrical resistance value and thus into an electric signal.
potentiometers The constructional technology of potentiometers is well known, as are the problems of low reliability, low precision of manual regulation and bulkiness which they involve.
the object of the present invention is to provide a position transducer which instead shows high reliability and compactness.
Another object of the invention is to provide a position transducer of the stated kind that can also be used in hostile environments.
a position transducer comprising a slider movable along a predetermined direction with respect to a reference body.
the transducer is characterized in that the reference body comprises a coil adapted to generate an electromagnetic field and provided with turns extending on a substantially flat surface passing along a straight line parallel to that which characterizes the predetermined direction.
the slider comprises an element made of conductive material adjacent the coil and coupled electromagnetically therewith.
the coil is connected in parallel to at least one capacitor with which it forms a resonant circuit.
the position transducer comprises essentially a coil 3 connected in parallel to at least one capacitor 4 with which it constitutes an LC parallel circuit resonant at a frequency Fo.
Resonant circuit 3, 4 constitutes, for example, the load of an oscillator 5 whose output 6 drives a peak detector 7.
coil 3 At frequency Fo, coil 3 generates an electromagnetic field in which a slider 8 is immersed that is movable relative to coil 3 along a predetermined direction indicated as 10 in Fig. 2.
coil 3 comprises turns extending on a substantially flat surface passing along a straight line parallel to that which characterizes shifting direction 10 of slider 8.
the latter is adjacent coil 3 and, in practice, its shifting direction 10 can be considered for simplicity's sake to be coincident with the aforesaid parallel line.
the turns of coil 3 consist of conductive tracks 11 deposited on a printed circuit base 12, with corresponding terminals 13 for connection to the remaining part of the circuit of Fig. 1.
Slider 8 which is preferably flat to allow for more compact dimensions, comprises essentially an element 14 realized in nonferromagnetic conductive material with high dissipation (for example stainless steel), coupled electromagnetically with coil 3.
element 14 is mounted on a nonconductive body 15 (shown by the broken line in Fig. 2) provided with molded edges (not shown) which engage corresponding edges of base 12 in such a way as to be able to slide relative thereto along direction 10.
the turns of coil 3 have a substantially quadrangular shape and are staggered, at least in one direction (toward the right in Fig. 2), along shifting direction 10 of slider 8.
the turns of coil 3 are staggered at a pitch or gradient A that is preferably constant and equal to or less than length B of element 14 regarded along direction 10.
turns of coil 3 are preferably close together in the direction at right angles to direction 10, and width L of smallest turn 16, regarded along this transverse direction, is at least equal to width M of element 14 of the slider.
oscillator 5 supplies parallel circuit 3, 4 with a prefera bly sinusoidal current having a constant mean value in such a way that circuit 3, 4 is resonant at frequency Fo, as already mentioned, and has a quality factors Q influenced by the power dissipated by element 14 of the slider, which is coupled electromagnetically with coil 3.
This coupling (and thus the power dissipated by element 14) is greatest when slider 8 is located in correspondence with (smallest) central turn 16 of coil 3, whereas it diminishes gradually when slider 8 is shifted toward the outermost turn (toward the right in Fig. 2).
the sinusoidal signal produced by oscillator 5 is transformed by peak detector 7 into a continuous signal.
a continuous signal is present at output 9 of peak detector 7 whose value is proportional to the position of element 14 of the slider along its shifting direction 10 relative to coil 3. In particular, this value increases with the shift of slider 8 from central turn 16 to the outermost turn of coil 3.
oscillator 5 is expediently dimensioned to work in class B in such a way that its output signal has a high dynamic value and the total transducer means is particularly sensitive.
the particular geometrical and dimensional interrelationship between coil 3 and element 14 as described above contributes advantageously, as has also been proven experimentally, to producing a substantially linear relation between the position of slider 8 along direction 10 and the voltage at output 9 of peak detector 7.
the typically selective frequency response curve of the parallel resonant circuit in which coil 3 is preferably connected allows for a signal to be obtained at output 6 of oscillator 5 whose amplitude varies considerably upon variation of the position of slider 8 along its shifting direction 10.
the inventive position transducer makes it possible for the inventive position transducer to have, advantageously, an elevated sensitivity so that it is unnecessary to use active amplification means (which always involve distortion) for the signal produced by oscillator 5. Consequently, the electric circuit of the trans ducer is also particularly economical.
the transducer is furthermore particularly reliable due to the total absence of electric sliding contacts between elements 3 and 8 and, unlike conventional potentiometers, it can be used even in hostile environments. For example, it can be used, without any danger of the materials deteriorating, inside a refrigerator or a freezer, where the environment is very cold and humid.
pitch A between the turns of coil 3 can be variable, also exponentially, and in this case length B of element 14 will preferably be equal to or greater than the smallest helical pitch of the coil.
length B of element 14 will preferably be equal to or greater than the smallest helical pitch of the coil.
coil 3 can be shaped in different ways, for example with a curved configuration, and the electric circuit for detecting the signal corresponding to the position of slider 8 can also be realized differently.
capacitor 4 can be omitted from the position transducer, or it can form with coil 3 a serial, instead of a parallel, resonant circuit, or element 14 can be made of ferromagnetic conductive material. In this latter case, the general operation of the transducer is substantially unchanged, the difference lying in the influence of element 14 on quality factor Q of the resonant circuit.

Landscapes

Physics & Mathematics (AREA)
General Physics & Mathematics (AREA)
Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
Magnetic Resonance Imaging Apparatus (AREA)
Transmission And Conversion Of Sensor Element Output (AREA)
Surgical Instruments (AREA)
Piezo-Electric Transducers For Audible Bands (AREA)
Electrophonic Musical Instruments (AREA)
Geophysics And Detection Of Objects (AREA)

EP89111971A 1988-07-22 1989-06-30 Transducteur de position Expired - Lifetime EP0351609B1 (fr)

Priority Applications (1)

Application Number	Priority Date	Filing Date	Title
AT89111971T ATE93960T1 (de)	1988-07-22	1989-06-30	Positionsumsetzer.

Applications Claiming Priority (2)

Application Number	Priority Date	Filing Date	Title
IT4574988		1988-07-22
IT8845749A IT1225118B (it)	1988-07-22	1988-07-22	Trasduttore di posizione.

Publications (3)

Publication Number	Publication Date
EP0351609A2 true EP0351609A2 (fr)	1990-01-24
EP0351609A3 EP0351609A3 (fr)	1991-03-06
EP0351609B1 EP0351609B1 (fr)	1993-09-01

Family

ID=11258041

Family Applications (1)

Application Number	Title	Priority Date	Filing Date
EP89111971A Expired - Lifetime EP0351609B1 (fr)	1988-07-22	1989-06-30	Transducteur de position

Country Status (5)

Country	Link
EP (1)	EP0351609B1 (fr)
AT (1)	ATE93960T1 (fr)
DE (1)	DE68908805T2 (fr)
ES (1)	ES2047064T3 (fr)
IT (1)	IT1225118B (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
FR2669418A1 (fr) *	1990-11-15	1992-05-22	Havre Lepii Universite	Dispositif de mesure de deplacement d'un objet.
GB2272771A (en) *	1992-11-23	1994-05-25	Mannesmann Ag	Inductive displacement detector
WO1997039312A1 (fr) *	1996-04-15	1997-10-23	Regal Components Ab	Capteurs de deplacement
EP1158266A1 (fr) *	2000-05-24	2001-11-28	Balluff GmbH	Dispositif de mesure de position
US6828780B2 (en)	2001-05-01	2004-12-07	Balluff Gmbh	Position measuring system having an inductive element arranged on a flexible support

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
DE102018222569A1 (de) *	2018-12-20	2020-06-25	Te Connectivity Germany Gmbh	Messeinrichtung zur Bestimmung einer Weg- und/oder Winkeländerung zwischen der Messeinrichtung und einem gegenüberliegenden Positionselement und Messverfahren
US11305368B2 (en) *	2020-01-30	2022-04-19	Illinois Tool Works Inc.	Inductive position sensor with switch function

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
JPS5513288B2 (fr) *	1973-06-18	1980-04-08
IE55855B1 (en) *	1984-10-19	1991-01-30	Kollmorgen Ireland Ltd	Position and speed sensors

1988
- 1988-07-22 IT IT8845749A patent/IT1225118B/it active
1989
- 1989-06-30 AT AT89111971T patent/ATE93960T1/de not_active IP Right Cessation
- 1989-06-30 ES ES89111971T patent/ES2047064T3/es not_active Expired - Lifetime
- 1989-06-30 DE DE89111971T patent/DE68908805T2/de not_active Expired - Fee Related
- 1989-06-30 EP EP89111971A patent/EP0351609B1/fr not_active Expired - Lifetime

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
FR2669418A1 (fr) *	1990-11-15	1992-05-22	Havre Lepii Universite	Dispositif de mesure de deplacement d'un objet.
GB2272771A (en) *	1992-11-23	1994-05-25	Mannesmann Ag	Inductive displacement detector
US5742161A (en) *	1992-11-23	1998-04-21	Mannesmann Aktiengesellschaft	Method and device for detecting displacement of valve rod movement in an electropneumatic position regulator with at least one proximity sensor
WO1997039312A1 (fr) *	1996-04-15	1997-10-23	Regal Components Ab	Capteurs de deplacement
EP1158266A1 (fr) *	2000-05-24	2001-11-28	Balluff GmbH	Dispositif de mesure de position
US6714004B2 (en)	2000-05-24	2004-03-30	Balluff Gmbh	Inductive position measuring system
US6828780B2 (en)	2001-05-01	2004-12-07	Balluff Gmbh	Position measuring system having an inductive element arranged on a flexible support

Also Published As

Publication number	Publication date
DE68908805T2 (de)	1993-12-23
DE68908805D1 (de)	1993-10-07
EP0351609A3 (fr)	1991-03-06
ES2047064T3 (es)	1994-02-16
IT1225118B (it)	1990-11-02
ATE93960T1 (de)	1993-09-15
IT8845749A0 (it)	1988-07-22
EP0351609B1 (fr)	1993-09-01

Publication	Publication Date	Title
EP0211142B1 (fr)	1991-08-14	Dispositif pour mesurer des déplacements
EP0215840B1 (fr)	1991-03-27	Capteur a bobine d'inductance
US4658153A (en)	1987-04-14	Planar coil apparatus for providing a frequency output vs. position
US5973494A (en)	1999-10-26	Electronic caliper using a self-contained, low power inductive position transducer
EP0119673A1 (fr)	1984-09-26	Transducteurs de force
GB1559631A (en)	1980-01-23	Straimstress detecting system
EP0351609A2 (fr)	1990-01-24	Transducteur de position
JPH08503778A (ja)	1996-04-23	磁性反転導体と一又は複数の磁気抵抗レジスタとからなる磁界センサ
US6922051B2 (en)	2005-07-26	Displacement and/or angle sensor with a meander-shaped measuring winding
US5247253A (en)	1993-09-21	Eddy current proximity sensing means and method useful for determining throttle position
US4064451A (en)	1977-12-20	Hysteresis compensated reed switch assembly for a position indicating system
US4350954A (en)	1982-09-21	Inductive type displacement transducers
US5049827A (en)	1991-09-17	Non-contacting potentiometer
EP0537747A2 (fr)	1993-04-21	Circuit oscillateur et commutateur de proximité l'utilisant
US2918666A (en)	1959-12-22	Condition responsive electrical system
US7511476B2 (en)	2009-03-31	Electromagnetic sensor systems and methods of use thereof
JPH07296671A (ja)	1995-11-10	電動機を制御するためのプッシュボタンスイッチ素子
GB2430750A (en)	2007-04-04	Position sensing apparatus and method
WO2005029132A1 (fr)	2005-03-31	Procede et appareil de detection de proximite de cible metallique a grande distance
CA2462248C (fr)	2013-04-16	Micro-commutateur avec circuit d'induction a impulsions
AU2002341117A1 (en)	2003-06-26	Electrical apparatus
JP2003152477A (ja)	2003-05-23	アナログ制御機構
JPS6222001A (ja)	1987-01-30	位置検出装置

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